How does aging affect bone health?

In most people, bone health declines in later life. This includes a decrease in BMD (usually beginning in the early 40s for men and late 30s for women); an increased risk of osteoporosis, bone fractures, and certain bone cancers; and a higher prevalence of degenerative bone/joint conditions (such as osteoarthritis). Among these age-related concerns, the increased risk of osteoporosis is the most common cause of bone disease in older adults.

This is because approximately 90% of our bone mass is acquired between birth and 20 years of age.^[1] Peak bone mass is maintained in men until their early 40s, and in women until their late 30s, at which point BMD begins to decline. The decline begins earlier in women due to the hormonal changes that occur during perimenopause and menopause, especially the decline in estrogen.^[2] After age 60, the rate of BMD loss in both men and women is around 1%–1.5% each year, and, by age 70, around 30%–40% of total bone mass is lost.^[2] People who achieve a higher peak bone mass early in life are at a significantly reduced risk of osteoporosis. While bone mass is influenced by genetics, diet and physical activity can also help build more bone during childhood and attenuate the decline that begins around midlife.